I was walking along a country road this afternoon when I spotted a dandelion in full sun-drenched bloom. Right away I remembered it was time to plant potatoes. Although this may sound like an “old wives’ tale” these associations are based in fact.
Phenology is the study of periodic plant and animal life cycles in relation to seasonal changes in climate. It means that cyclic biological activity (things that happen every year) is often dependent on annual changes in temperature. Everyone has seen this. For example, cold weather until late in the spring means that flowers will bloom later . . . and you may have to feed your bees longer.
Farmers have long known they could estimate planting times by looking at the wild plants. By continued observation of what happened and when, they compiled rules of thumb they could use for planting.
In my dandelion example, farmers learned that when the soil was warm enough to produce a dandelion bloom, it was warm enough to plant a potato “seed piece” in the ground.
A search through old almanacs and calendars will yield lots of these little gems, including associations that help predict flowering, ripening of fruits, unfolding of leaves, hatching of eggs, and bird migrations. More recently, phenology has been used to predict the effect of climate change on these and other annual biological events.